The Law of The Yama Manga

Summary:
Zuo Hui is an introverted high school student from a poor family. One day, when secretly working a part time job outside, he is caught by his mother. After the two have a heated dispute, Zuo Hui angrily turns away and leaves. Distracted by thoughts of guilt and regret, he loses footing and falls down a rain-flooded sewer hole. When Zuo Hui awakes he finds himself in a sealed room surrounded by a group of diverse strangers and with a rope around his neck. The more he struggles to take off the rope, the tighter it becomes. Where is this? Who are you people? And who exactly is that self-proclaimed “Yama”?